Alltrex had not touched tf2 before he started highlander. Coming from esea premier cs:go, he came into team fortress with an experienced competitive outlook. He knows what teams need to function at a high level: coordination, roles, but most importantly, discipline.
In lower divisions especially, a lot of players focus on what they want the game to be, and not what the game actually is. Pyros feed for damage and force themselves into ubers, “Pyro is an action class!”. Spies go for trickstabs and unimportant picks, “Look at this clip guys!”. Players like these often have great stats, and get caught in peoples memory.
But highlander is not about logs and clips, it’s about teamwork and doing your job. For a lot of people, proper play (often being passive and playing your life), is boring compared to more flashy/mechanical styles of play. Some people are just unable/ unwilling to adapt to what their team needs.
Alltrex is a valuable player because he never learned to care about mechanics or being flashy, he came into this game with a teamplay oriented mindset. He didn’t pick spy because of it’s interesting movement tech or trickstabs, he picked spy because that’s what his newcomer team was missing. In a similar vein, he didn’t learn to frag out and feed for picks, because his team needed calls and help coordinating. Alltrex has no notion of “what do i want my class to do?”, only the mindset of “what can my class do to benefit the team?”
Combine that mindset with a passion for the game, a desire to improve, and the ability to found a sense of community - you will not only have a strong spy, but an incredible asset to any team.